Gauge



Oct. 19, 1937.

H. M. ST. JOHN ET AL GAUGE Filed Dec. 14, 1935 M 4 50 Mid/u ATTORNEY Patented Oct. 19, 1937 PATENT OFFICE GAUGE Harry M. St. John and Thomas Rynalski, De-

troit, Mich., assignors to Detroit Lubricator Company, Detroit, Mich, a corporation of Michigan Application December 14, 1935, Serial No. 54,445

- a g 7 Claims.

Our invention relates generally to gauges for indicating the quantity of liquid in a container and'more particularly to the operating means therefor. I

One of the objects of our invention is to pro- .vide a new and improved gauge for indicating r manufacture.

the'quantity of liquid in a container.

Another object of our invention is to provide a gauge of the above mentioned character which is efficient in operation'and yet economical to The invention consists in the improved conflstruction and combination of parts to be more fully described hereinafter and the novelty of -which will be'particularly pointed out and distinctly claimed. i

f In the accompanying drawing, to be taken as a part otthis specification, we have fully and .clearly illustrated our invention, in which draw- Figure 1 is a view in vertical central cross section of a liquid container having our improved gauge associated therewith; I

' Fig. 2 is a view similar to Fig. 1 showing the position of the indicating and operating means of the gauge when the container is empty, and

- Fig. 3 is a view of a float which constitutes a part of our gauge.

Referring to the drawing by characters of reference, the numeral I designates a reservoir tank .or container on'the top outer wall of which is mounted the indicating mechanism'of our gauge and which is housed within a housing 2. Any

suitable type of indicating mechanism may be employed'and mounted on the container in any suitable manner. The container I has a centrally located aperture 3 in its top wall and fixed to the outer wall of container I, such as by welding, there is a reenforcing plate 4 having an aperture 5 which aligns with aperture 3 in the container I. The aperture 5 in the plate 4 may be defined by an annular upturned flange 6 which may be internally threaded for receiving an externally threaded tubularmember 'l which is also internally threaded for receiving a lower end portion of the housing 2. The lower end of housing 2 is open and has an internal, upwardly facing shoulder on which an abutment member 8 seats. The abutment member 8 may be held in position against its seat by engagement therewith of the lower end of a tubular, transparent member Ill which may be glass and which may be sleeve fitted into housing 2.

Disposed within housing 2 there is a calibrated coil spring ll which has one end abutting the abutment member 8 and its other or upper end abutting the underside of an annular flange or head I2 formed on the upper end of a movable indicator or supporting member l3. The supporting member or indicator I3 is in the form of a rod which extends centrally through spring H and through an aperture in the abutment member 8 and has its lower end shaped in the form of ahook, as at M. In this type of indicator the head l2 of rod [3 serves as the pointer and is visible through an opening 15 in the wall of housing 2 and through the glass tubular member H] which surrounds rod l3 and spring H. The wall of housing 2, adjacent the opening therein through which the indicator is visible, may be provided with suitable markings or indicia cooperable with the head E2 of rod l3 to indicate the quantity of liquid in container l In order to provide for efficiently operating the indicating mechanism in accordance with changes in the quantity of liquid in the container, we provide a flexible and submergible weight, preferably a metallic chain It which acts to move rod l3 downwardly, and we provide a float H which acts to vary the effective weight of the chain acting on rod 13 in accordance with changes in the quantity of liquid in container I. One end -of the .chain 16 may be connected to the lower or hooked end of rod I3 while the other end is connected to the float l1, and this chain is preierably constructed so that it will not kink and is preferably sufficiently long so that when the con tainer is empty, as in Fig. 2, and the pointer or head. l2 points to empty, the float will seat on the bottom wall of the container. The specific gravity of float I! with respect to the specific gravity of the liquid in the container is such that it will float substantially at the surface of the liquid. In order to minimize the possibility of gauge errors occurring, due to changes in the buoyancy of the float upon variations in the specific gravity of the liquid, an elongated float, as shown in Fig. 3, or one which has a relatively large horizontal cross sectional area in proportion to its volume may be employed.

The operation of our gauge is as follows: When there is liquid in container l, as indicated by the line L-L of Fig. 1, the chain It will have a loop portion which will be below the liquid level, or be submerged. Of the submerged looped portion of chain l6, substantially one half is supported by float I! while the other half of the submerged portion, and the portion of the chain above the liquid level, is supported by the calibrated spring ll via rod l3. The weight of substantially one half of the submerged portion of the chain, plus that portion above the liquid level, is the eifective weight acting to compress spring H and is variable as the liquid level varies. It will be seen that as the level of the. liquid decreases more of the weight of the chain will be supported by spring I I, and when the container becomes empty the entire weight of the chain will be acting to compress spring H so that as the float moves downward with the decreasing liquid level the pointer i2 will correspondingly move downward and indicate the quantity of liquid in the container.

What we claim and desire to secure by Letters Patent of the United States is:

1. In a device having a movable indicator for indicating the quantity of liquid in a container, a flexible and submergible weight member operatively connected to said movable indicator for operating the same, and a float in said container and connected to said flexible weight member, said float being operable to support a portion of the weight of said weight member with said supported portion being variable in accordance with changes in liquid level to correspondingly vary the eiTective weight acting on said movable indicator.

2. In a device having a movable indicator for indicating the quantity of liquid in a container, a float in said container, and a flexible weight member depending from said indicator for oper-- ating the same and having one end connected to said float, said float beingfloatable adjacent to the level of the liquid and operable to support a portion of the adjacent end of said flexible weight member with said portion being variable in accordance with changes in the quantity of liquid in the container to correspondingly vary the portion of the weight member depending from said indicator.

3. In a device having a movable indicator for indicating the quantity of liquid in a container, a submergible metallic chain operable by its weight to operate said indicator and having operative connection therewith, and a float in said container and attached to one end of said chain, said float being operable to support substantially one half of the submerged portion of said chain with the submerged portion being variable in length in accordance with changes in liquid level whereby the effective Weight of the chain acting on said indicator is correspondingly varied.

, 4. In a device for indicating the quantity of liquid in a container, a flexible and submergible metallic chain extending into the liquid in the container, supporting means for one end of said chain, a float disposed in said container and adapted to float at a point in the liquid so that it supports a depending portion of the other end of said chain with the remainder of the chain being supported by said supporting means, the lengths of chain supported by said float and said supporting means varying as the level of the liquid varies, and indicator means associated with said sup--' porting means and operable in response to variation in the length of said chain supported thereby for indicating the quantity of liquid in said container.

5. In a device for indicating the quantity of liquid in a container, a submergible metallic chain extending into said container, a resilient support for one end of said chain, a float disposed in the container and connected to the other end of said chain, said float being adapted to float substantially at the surface of the liquid and being operable upon variation of the level of liquid to vary the effective weight of the chain supported by said resilient supporting means, and indicator means associated with said resilient support and movable thereby for indicating the quantityof liquid in said container.

6. In a device forindicating the'quantity of liquid'in a container, an indicating means including a calibrated spring acting to move an indicator in one direction, a flexible and submergible metallic chain operable to exert a force opposing said spring to move said indicator in the opposite;

direction, said chain having one end operatively connected to said spring, a float in said container and connected to the other end of said chain, said chain having a submerged portion with the float being operable to support a portion of the weight of said submerged portion with the weight of the remaining portion of said chain acting against the force of said spring and being variable in accordance with changes in the quantity of liquid in the container to correspondingly move said indicator.

7.'In a liquid level indicator, a metallic chain actuating, member submergible in the liquid, an

indicator secured to one end of the chain, said indicator being moved by the weight of said chain, means opposing movement of said indicator and balancing the weight of the chain acting on 'said indicator for each position of the indicator, and a single float connected to the other end of said chain and supporting a portion. 

